According to David Cronenberg's epochal Videodrome, there's nothing more dangerous than "a philosophy", an adage that applies to life in general and horror cinema in particular. Stepping up a gear from their altogether more generic feature debut Dead Hooker in a Trunk, the "twisted sisters" Jen and Sylvia Soska hit their stride with American Mary (2012 Universal, 18), a film that, despite its tight production constraints, wields its ideas like weapons and packs more of a punch than many of its more bloated competitors.

Centring on a young surgeon (Ginger Snaps star Katharine Isabelle) who turns the tables on her abusive professional elders through amateur experiments with a scalpel, this wincingly bloody satire delves deep into the fringe world of body modification, becoming a sadomasochistic companion piece to Crash with real underground bite. Adhering to the Roger Corman principles of exploitation cinema (as long as you've got a couple of scenes in a strip club, you can do what you want), American Mary addresses issues of gender equality and physical objectification in a manner just sleazy enough to slip under the gore-hounds' radar.

At times it reminded me of Mitchell Lichtenstein's underrated Teeth, a tale of avenging vagina dentata that mixes gross-out with grey matter to delightfully subversive effect. Isabelle makes for a charismatic heroine, forceful and funny, while the Soskas indulge their fetish-inflected sensibilities with real wit and verve. There are also plenty of quietly reflective moments amid the craziness in which characters are allowed to breathe, ensuring that this never becomes a mere freak show. The worthy hit of last year's FrightFest that enjoyed only a brief UK theatrical outing, this deserves to find fans outside of the hardcore bat-pack on DVD and promises great things for its twisted creators in the future.

While American Mary may be a horror treat, the Adam Sandler "comedy" That's My Boy(2012, Sony, 15) is just plain horrible. One of the very worst films of last year (along with Keith Lemon: The Film), this ill-judged barf-fest attempts to get us to see the funny side of statutory rape and incest, an endeavour in which it fails spectacularly, if unsurprisingly.

Sandler plays the hideous man-child who impregnated his teacher as a kid and is now forced to forge paternal bonds on the eve of his estranged son's nuptials. Withheld at the last minute from UK film critics for reasons that should be evident, this is less side-splitting than jaw-dropping, the kind of movie that leaves you wondering whether Sandler actually made it for a dare. Honestly, unanaesthetised rectal surgery would be funnier. If you're stupid enough to buy or rent That's My Boy, then frankly you deserve everything you get. Just don't come crying to me when the inevitable wave of nauseous self-loathing finally breaks over you. Oh, and Susan Sarandon – shame on you.

If the cast of The Sweeney (2012, Entertainment One, 15) turned up at a screening of That's My Boy they'd presumably arrest everyone involved for crimes against comedy, but only after kicking a few doors in, cracking some heads and driving a motor straight through a bloody wall before dusting down their blouson leather jackets and going down the boozer, like proper old-school rozzers.

That director Nick Love's self-consciously modern reinvention of the 70s sheepskin coat franchise should be laddy as all hell is no surprise – from The Football Factory to The Business to Outlaw, Love's palette is nothing if not clearly defined (although co-writer John Hodge's back catalogue includes Trainspotting and Shallow Grave). What's more refreshing is Ray Winstone's wounded-bear portrayal of Jack Regan, a dinosaur who looks admirably ridiculous in his underpants, and about whom there is a genuine air of pathos. Musician-turned-actor Ben Drew, aka Plan B, is less adventurous in the Dennis Waterman role, but at least Love's perennially insufferable mucker Danny Dyer doesn't get a look in.

Based on a Beth Raymer's memoir, Stephen Frears's Lay the Favourite(2012, Entertainment One, 15) squanders a star-studded cast on a half-baked romanticised bookie yarn that will have you longing for the comparative cutting edge of The Grifters. Rebecca Hall is reliably terrific as the former waitress learning the betting ropes under the tutelage of Bruce Willis's crotchety old rogue and his tight-faced harridan wife, an unflattering role that Catherine Zeta-Jones embraces with admirable gusto. Meanwhile, Vince Vaughn plays an annoying, loud-mouthed asshole with appalling taste in shirts, so no change there.

It's not terrible, just terribly televisual; the sort of film that might pass muster on a long-haul flight but proves less tempting for anyone with easy access to an exit. There are a couple of tight-lipped laughs along the way and Hall continues to charm, but despite the star wattage this is remarkably unmemorable.

In cinemas the Jewish exorcism movie The Possession (2012, LionsGate, 15) showed up in a version trimmed to an American PG-13 rating, meaning that everything was toned down for the young teen market. Sadly, even in its uncut edition on DVD, this remains drearily dull fare, despite the presence of producer Sam Raimi and Nightwatch director Ole Bornedal. When a young girl opens a carved wooden box bought in a yard sale, demons are duly released and much hissing, huffing and general ooga-booga contortions ensue. It's all desperately derivative and frankly a bit dull. Boo! But not in the scary sense.